One of President Obama's most controversial judicial nominees made a rare second appearance before the Senate Judiciary Committee Wednesday and just like his first go-around, Goodwin Liu was met with fierce Republican opposition that has played a key part in holding up his confirmation for more than a year.

The committee's ranking Republican, Sen. Charles Grassley, R-Iowa, set the tone for the hearing when he reiterated concerns from many conservatives that Liu's writings, speeches, judicial views and temperament aren't compatible for a lifetime appointment to the Ninth Circuit U.S. Court of Appeals.

"I am concerned about his understanding or appreciation of the proper role of a judge in our system of checks and balances," Grassley said.

Liu is a University of California-Berkeley law professor and has been associate dean since 2008. He graduated from Yale Law School in 1998, won a Rhodes scholarship to Oxford and in 2008 worked on President Obama's transition team.

His nomination has been hotly contested by committee Republicans who think he'll too easily fit in with a Ninth Circuit already seen as a liberal bench.

Feinstein also said she was troubled that only one Republican member of the committee had personally met with Liu and encouraged her GOP colleagues to do so. She told a story about sharing a family dinner with Liu and found him to be a scholar of formidable intellect and a "very interesting and talented young man."

Later in the hearing, Sen. Tom Coburn, R-Okla., said he looked forward to meeting with Liu.

The hearing plowed over much of the same ground as last April's appearance with great attention placed on comments Liu made about now Justice Samuel Alito in 2006. "In Judge Alito's America, the police may shoot unarmed Americans ... the FBI may install a camera where you sleep ... an all white jury may convict a black man to death," Liu stated.

On Wednesday, Liu said he's thought a lot about that testimony and says it was not an appropriate way to describe Alito as a judge or a person. He said it was harsh, provocative and unnecessary.

Under questioning from Coburn to explain why he had included that as part of his testimony, Liu simply explained, "It was poor judgment."

Some Republican senators also expressed concern over the breadth of the 40-year-old's career. Sen. Jeff Sessions said Liu had "no real experience" as a practicing lawyer or as a judge. Liu replied that strengths including his tenure as a legal scholar giving "rigorous inquiry" to difficult questions should weigh in his favor.

He also cited his experience as clerk to D.C. Circuit U.S. Court of Appeals Judge David Tatel, who told him to always "look at the record" when it comes to reviewing a case. Liu also clerked for Supreme Court Justice Ruth Bader Ginsburg.

It didn't appear that Liu said anything overly controversial or contrary to what he offered last year. If confirmed, he said he would maintain fidelity to the Constitution and uphold all decisions handed down by the Supreme Court.

Liu repeatedly discounted suggestions that he would ignore legal precedents in favor of his own personal views. Sen. John Cornyn, R-Texas, said he had trouble believing that Liu could "wipe the slate clean" and follow the law.

Cornyn said he's troubled by what he called a kabuki theater of past nominees who've come before the committee and experienced a "nomination conversion" to get approval.

In a back-and-forth with Feinstein who presided over the hearing, Cornyn said Justice Sonia Sotomayor was less than forthright when she said the Constitution protects an individual right to keep and bear arms but last year voted against making that right applicable to the states.

Apparently likening Liu to Sotomayor and others who've fallen into his disfavor, Cornyn said, "I'm not convinced this is the right job for you."

Sessions also objected to what he called contradictions between Liu's testimony and writings, which he said represented "the most advanced state of the activist judicial philosophy I've [ever] seen."

Liu's nomination passed the committee last year on a party-line vote and was never called to Senate floor for final passage. He was re-nominated by President Obama in January along with several other troubled judicial nominees.

Members of both parties have echoed an interest in recent weeks to be less divisive and move more rapidly in processing picks. It's not clear how Liu's longstanding nomination fits into this recent spirit of cooperation.